Red like regular deer (3)
I believe the answer is:
elk
'deer' is the definition.
(type of deer)
'red like regular' is the wordplay.
'regular' indicates alternate letters.
'red'+'like'='redlike'
The alternating letters of 'redlike' are 'ELK'.
(Other definitions for elk that I've seen before include "Asian moose" , "Large northern deer" , "Moose-like deer" , "Wapiti" , "Big deer" .)